This invention relates to a print control device for a thermal printer used in calculator printers and typewriters, etc., which print by a thermal head having thermal printing elements for contacting a thermal sensitive recording medium.
With the prior art thermal printer, the on-time of current supply to the thermal printing elements is controlled by either software or hardware. Software has the advantage that it is easy to control the printing density adjustment but the disadvantage that when the print flow is uncontrollable due to low battery voltage, noise, or static electricity, the printing signal continues to be applied to the thermal elements, which results in overheating and damage to the thermal elements.
With hardware-controlled on-time, the above disadvantages do not exist but the disadvantage of the on-time being set and therefore not being able to control the print density in relation to a printing pattern, does exist.